1. Field of the Invention
The present invention relates to key pad assemblies, primarily for safes and other secure containers.
2. General Background and State of the Art
Safes and other secure containers have traditionally used combination locks for controlling and authorizing entry. Locks had been mechanical and relied on a person dialing a correct combination on a rotating dial. The rotation positioned mechanical elements within the lock such that dialing the correct combination allowed a locking bolt to release the container door. For example, traditional mechanical locks, such as Gartner, U.S. Pat. No. 3,968,667 (1976), rely on a dial rotating tumblers. Proper dial rotation aligns gates in the tumblers. Once the gates are aligned, a fence on a fence lever can enter the aligned gates. Continued rotation of the dial and tumblers pulls the fence lever and withdraws the bolt.
Electronics have replaced mechanical structures in many locks. Electronic locks can use electronics rather than aligned tumbler wheels to sense entry of the correct combination. The electronics can sense the rotary position of a combination lock dial, or a key pad can replace the combination dial. Consequently, instead of dialing a number, e.g., 72, the user would first push the xe2x80x9c7xe2x80x9d and then the xe2x80x9c2xe2x80x9d keys for the same result. Uyeda, U.S. Pat. No. 5,134,870 (1992) and Gartner, U.S. Pat. No. 5,136,870 (1992) are examples of a key pad entry system for a safe and door lock, respectively.
When the lock is used to secure entry to a container, the electronic components are mounted on a housing inside the container door. The housing contains a battery and a circuit board, which contains the electronic circuitry controlling the lock. The key pad is on the outside of the housing to be accessible to the user. Therefore, a cable must extend between the key pad and the circuit board for transmitting signals between the two components. Additionally, the battery must be secured, and wires must connect the battery to the circuit board.
Batteries power most electronic locks. One could mount the battery within the safe or container. If the battery fails, however, the lock is inoperative, rendering it impossible to use the lock to access the inside of the container. Therefore, mounting the battery in the key pad housing and making the battery accessible without having to open the safe is desirable.
The key pad is on the outside of the key pad housing, but the circuitry is within the housing. Therefore, the cable that carries signals from the keys must extend through a wall of the key pad housing from the key pad to the circuit board. During assembly and use, the cable can separate from the circuit board. Cable bending can also cause a break in one of the conductors in the cable.
Traditionally, the key pad is parallel to the safe or container wall. Thus, it usually is in a vertical plane. Often, the user""s eyes are higher than the key pad so he or she looks down and at an angle to it. Accordingly, having a flat key pad with its surface parallel to the door may make the key pad more difficult to see.
One object of the present invention is to disclose and provide a key pad housing in which the external parts such as the key pad connect to the internal parts and circuitry securely. Another object of the present invention is the disclosure and provision of a key pad housing with an angled face that can be seen when the eye level is above the key pad. Another object is to disclose and provide a way of securing a battery that powers the internal circuitry and yet is accessible for replacement.
These and other objects of the present invention will be apparent with the drawings and the detailed explanation of the exemplary embodiments.
The key pad assembly of the present invention includes a housing that attaches to a secure container. The housing has a front wall, and a key pad attaches to the front or outside face of the front wall. A generally cylindrical side wall extends back from the front wall. The side wall is truncated at an angle so that as the edge of the side wall seals against a safe or container door, the front face of the key pad housing is at an angle to the door. Where the side wall is widest, the side wall has a removable section through which a battery can be inserted.
A cable extends through an opening in the front face from the key pad to a circuit board that mounts the combination sensing circuit. The cable is flat with multiple electric conductors through it. The cable also has a slot. When the key pad and circuit board are properly assembled, the slot in the cable fits over a pin extending from the rear face of the front wall of the housing. The pin secures the cable so that it is not pulled from its connection with the key pad or the circuit board. Other pins within the housing mount the circuit board.
Parallel walls from the rear of the front face create a cavity for the battery. Small walls near the bottom of the battery chamber support the bottom of the battery. Each of the side walls that create the battery chamber has a shaft with an opening that extends through the front wall. The shafts supply support for bolts attaching the housing to the secure container. The key pad covers those openings.